On-Board Exhaust Emission Measurements of Vehicles Using a Portable Emission Measure System

It's necessary to study vehicle emission characteristics and emission factors for establishing vehicle emission inventory and the corresponding control strategy. The paper presents the results of on-board exhaust emission tests of diesel and Compressed Natural Gas vehicles under real road conditions of city traffic using a PEMS equipment. The results show that the PEMS equipment can be used to test vehicle exhaust emission, the on-board test reflects the actual emissions from vehicles under real-world roads. The average emission factors of CO, NOx and THC of diesel vehicles under real-world conditions are 10.07g/km, 11.79g/km, 1.72g/km, respectively. The test results also show that CO and NOx emission factors of CNG vehicle are lower than these of diesel vehicle, while the THC emission factor is higher.